1. Field of the Invention
This invention relates to silver halide color photographic light-sensitive material, and more particularly to silver halide color photographic light-sensitive material which permits the prevention of discoloration and fading by light of dye image areas and unexposed areas of dye images obtained by development after imagewise exposure.
2. Description of the Prior Art
In general, dye images obtained by the development of silver halide color photographic light-sensitive material comprise azomethine or indoaniline dye formed by the reaction of an oxidation product of an aromatic primary amine developing agent and a color coupler. These dye images have limited stability to light and to heat under humid conditions; when they are exposed to light for extended periods of time or stored under conditions of high temperature and humidity, discoloration and fading of the dye image areas and discoloration of white areas (that is, areas where a dye image is not present) occurs, leading to reductions in image quality.
Such discoloration or fading of the dye image and discoloration of the white areas is a major problem in silver halide color photographic light-sensitive materials.
The discoloration and fading of the dye image and discoloration of the white areas is considered to be caused mainly by ultraviolet or visible rays, and therefore a number of techniques using ultraviolet ray-absorbing agents or anti-fading agents have been developed to prevent the discoloration and fading due to light. In addition, a number of techniques have been proposed in which couplers of low fading are used.
Examples of such methods using magenta couplers are described in U.S. Pat. No. 3,519,429. Use of hydroxycumarones as an antioxidant is described in U.S. Pat. No. 3,432,300. The use of anti-fading agents containing phenolic hydroxy groups is described in U.S. Pat. No. 3,698,909, and the use of alkyl ethers as an antioxidant is described in Japanese Patent Application (OPI) No. 77526/78 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application").
Although these compounds have some effect in preventing the discoloration and fading of dye images, the effect is not always sufficient, and, moreover, many of them exert adverse side effects, such as reduction of hue, fog formation, insufficient dispersion of an antioxidant into oils (organic solvents having a high boiling point) which prevents the formation of stable oil droplets, and cause crystallization of the antioxidant. Thus, compounds exhibiting sufficiently excellent effects have not yet been discovered.
It is known that oxygen is also responsible for the discoloration and fading of the dye image and discoloration of the white areas, and therefore techniques for preventing the discoloration and fading by preventing oxygen from coming in contact with the dye images have been proposed. For example, such techniques are described in Research Disclosure, Vol. 15162, page 82 (November 1976), and Japanese Patent Application (OPI) Nos. 11330/74 and 57223/75 wherein an oxygen-shielding layer formed from a substance having a low oxygen permeability is used to cover the dye images.
According to such methods, after the development of the color photographic light-sensitive material, the dye images are covered with the oxygen-shielding layer, for example, by laminating a polyethylene terephthalate film thereon. If the dye images are completely covered with the oxygen-shielding layer and prevented from coming into contact with oxygen, the magenta and yellow color dye images are greatly improved in their discoloration and fading properties. However, the discoloration and fading of the cyan color image formed from cyan couplers which are normally used in silver halide color photographic light-sensitive material (such as those represented by the formula (VI), as will be explained infra) is accelerated.
For silver halide color photographic lightsensitive material including a sheet of paper as a support (referred to hereinafter merely as "a color light-sensitive material"), anilinopyrazolone based couplers are preferably used because of good hue and color-forming efficiency. However, these couplers have the serious drawback that their use results in occurrence of discoloration and fading of the dye image and discoloration of the white areas.
Therefore it has been strongly desired to develop a technique which permits the use of such couplers as are described above without the occurrence of discoloration and fading.
With respect to the development of more recent color light-sensitive materials, rapid processing has increasingly been of great importance, and the conventional so-called three-bath processing (consisting of color development, bleach-fixing, and stabilization) is often being replaced with two-bath processing (consisting of color development and bleach-fixing). This two-bath processing, however, suffers from the disadvantages that the dye images obtained are inferior in stability and are subject to discoloration and fading.
Moreover, in the rapid development processing of color light-sensitive material, benzyl alcohol is sometimes incorporated into the color-forming developer for the purpose of shortening the development time by accelerating the color development. Such a developer, however, readily causes rapid discoloration and fading of the dye images formed.
Therefore it has been strongly desired to develop a color light-sensitive material which, even when subjected to such a rapid development processing, does not result in discoloration and/or fading of dye images.